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1 | /* -*-c-*- |
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2 | * |
3 | * Higher-level key unpacking |
4 | * |
5 | * (c) 2000 Straylight/Edgeware |
6 | */ |
7 | |
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8 | /*----- Licensing notice --------------------------------------------------* |
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9 | * |
10 | * This file is part of Catacomb. |
11 | * |
12 | * Catacomb is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU Library General Public License as |
14 | * published by the Free Software Foundation; either version 2 of the |
15 | * License, or (at your option) any later version. |
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16 | * |
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17 | * Catacomb is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | * GNU Library General Public License for more details. |
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21 | * |
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22 | * You should have received a copy of the GNU Library General Public |
23 | * License along with Catacomb; if not, write to the Free |
24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
25 | * MA 02111-1307, USA. |
26 | */ |
27 | |
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28 | /*----- Header files ------------------------------------------------------*/ |
29 | |
30 | #include <mLib/dstr.h> |
31 | |
32 | #include "key.h" |
33 | #include "key-data.h" |
34 | |
35 | /*----- Main code ---------------------------------------------------------*/ |
36 | |
37 | /* --- @key_fetchinit@ --- * |
38 | * |
39 | * Arguments: @const key_fetchdef *kf@ = pointer to base definition |
40 | * @key_packstruct *kps@ = pointer to destination packing def |
41 | * @void *p@ = pointer to destination block |
42 | * |
43 | * Returns: Pointer to packing definition. |
44 | * |
45 | * Use: Initializes a packing definition (@key_packdef@ structure). |
46 | * If @kps@ is null on entry, an appropriately sized block is |
47 | * allocated automatically. Otherwise it must be large enough. |
48 | */ |
49 | |
50 | static size_t kfcount(const key_fetchdef *kf) |
51 | { |
52 | size_t n = 1; |
53 | while (kf->name) { |
54 | n++; |
55 | if (kf->kf) |
56 | n += kfcount(kf->kf); |
57 | kf++; |
58 | } |
59 | return (n); |
60 | } |
61 | |
62 | key_packdef *key_fetchinit(const key_fetchdef *kf, |
63 | key_packstruct *kp, void *p) |
64 | { |
65 | size_t n = 1 + kfcount(kf); |
66 | key_packdef *kpd; |
67 | key_packstruct *kps; |
68 | char *cp = p; |
69 | |
70 | /* --- If @kps@ is null, count the entries and allocate --- */ |
71 | |
72 | if (kp) |
73 | kp->name = 0; |
74 | else { |
75 | kp = xmalloc(n * sizeof(*kp)); |
76 | kp->name = (char *)kp; |
77 | } |
78 | |
79 | /* --- Fill in the top part --- */ |
80 | |
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81 | kp->kp.e = KENC_STRUCT; |
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82 | kp->kp.p = &kp[1]; |
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83 | kp->kp.kd = 0; |
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84 | kpd = &kp->kp; |
85 | |
86 | /* --- Initialize for the main loop --- */ |
87 | |
88 | kps = kp + n; |
89 | n = 0; |
90 | kp++; |
91 | |
92 | /* --- Iterate over the entries in the table --- * |
93 | * |
94 | * The end of the target block is used as a stack to record where |
95 | * substructure is meant to occur. The integer @n@ is the depth of the |
96 | * stack; @kps@ is a full descending stack pointer. The @kp.p@ member of a |
97 | * stack element points back to an entry with substructure, the @kp.p@ |
98 | * member of which refers to the @kf@ table for the substructure. |
99 | * |
100 | * This should all be about as clear as mud. |
101 | */ |
102 | |
103 | for (;;) { |
104 | |
105 | /* --- Blat out a level's worth --- */ |
106 | |
107 | while (kf->name) { |
108 | kp->name = kf->name; |
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109 | kp->kp.e = kf->e; |
110 | kp->kp.kd = 0; |
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111 | if ((kf->e & KF_ENCMASK) != KENC_STRUCT) |
112 | kp->kp.p = cp + kf->off; |
113 | else { |
114 | (--kps)->kp.p = kp; |
115 | kp->kp.p = (void *)kf->kf; |
116 | n++; |
117 | } |
118 | kf++; |
119 | kp++; |
120 | } |
121 | (kp++)->name = 0; |
122 | if (!n) |
123 | break; |
124 | |
125 | /* --- Pop an entry from the stack --- */ |
126 | |
127 | { |
128 | key_packstruct *kkp = (kps++)->kp.p; |
129 | kf = kkp->kp.p; |
130 | kkp->kp.p = kp; |
131 | n--; |
132 | } |
133 | } |
134 | |
135 | /* --- We're done --- */ |
136 | |
137 | return (kpd); |
138 | } |
139 | |
140 | /* --- @key_fetch@ --- * |
141 | * |
142 | * Arguments: @key_packdef *kp@ = pointer to packing structure |
143 | * @key *k@ = key file containing desired key |
144 | * |
145 | * Returns: Error code, or zero. |
146 | * |
147 | * Use: Fetches an unpacked key from a packed one. |
148 | */ |
149 | |
150 | int key_fetch(key_packdef *kp, key *k) |
151 | { |
152 | dstr d = DSTR_INIT; |
153 | int e; |
154 | |
155 | key_fulltag(k, &d); |
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156 | e = key_unpack(kp, k->k, &d); |
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157 | dstr_destroy(&d); |
158 | return (e); |
159 | } |
160 | |
161 | /* --- @key_fetchbyname@ --- * |
162 | * |
163 | * Arguments: @key_packdef *kp@ = pointer to packing structure |
164 | * @key_file *kf@ = key file containing desired key |
165 | * @const char *tag@ = user's tag describing the key |
166 | * |
167 | * Returns: Error code, or zero. |
168 | * |
169 | * Use: Fetches a named key from a key file and unpacks it |
170 | * conveniently. |
171 | */ |
172 | |
173 | int key_fetchbyname(key_packdef *kp, key_file *kf, const char *tag) |
174 | { |
175 | dstr d = DSTR_INIT; |
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176 | key_data **kd; |
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177 | int e; |
178 | |
179 | if (key_qtag(kf, tag, &d, 0, &kd)) |
180 | e = KERR_NOTFOUND; |
181 | else |
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182 | e = key_unpack(kp, *kd, &d); |
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183 | dstr_destroy(&d); |
184 | return (e); |
185 | } |
186 | |
187 | /* --- @key_fetchdone@ --- * |
188 | * |
189 | * Arguments: @key_packdef *kp@ = pointer to packing structure |
190 | * |
191 | * Returns: --- |
192 | * |
193 | * Use: Frees a packing structure. If the structure was allocated by |
194 | * @key_fetchinit@ then it is freed. |
195 | */ |
196 | |
197 | void key_fetchdone(key_packdef *kp) |
198 | { |
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199 | key_packstruct *kps = |
200 | (key_packstruct *)(((char *)kp) - offsetof(key_packstruct, kp)); |
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201 | key_unpackdone(kp); |
202 | if (kps->name) |
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203 | xfree(kps); |
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204 | } |
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205 | |
206 | /*----- That's all, folks -------------------------------------------------*/ |